I have a 2000 25 outlaw,volt meter use to read 12 volts ,now under 12 almost 10.5 .batterys read 13.6 to 14 on high idel,alt reads same,rear of gauge reads low.

I had somewhat the opposite - always reading higher-- it was related to checking the ground on the instrument - I loosened the nuts holding the wires and cleaned the contacts - all was well after that. .

In addition, I would check the voltage at the meter and verify that in fact it is reading the same as the battery and alternator.

good luck

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